In the title spiro-indeno-quinoxaline compound, C(22)H(14)N(6)O·C(2)H(6)O, the five-membered ring of the indene unit and the pyran ring are perpendicular [89.11 (3)°]. In the crystal, N-H⋯N hydrogen bonds connect the spiro-indeno-quinoxaline mol-ecules, and the ethanol solvent mol-ecules complete the hydrogen-bond network via O-H⋯N and N-H⋯O inter-actions.

A series of functionalized spiro[indoline-3,2'-oxiran]-2-ones was efficiently synthesized by Darzens reaction of phenacyl bromides with isatins both with N-alkyl groups and without N-substituent in the presence of potassium carbonate as a base catalyst. When two equivalents phenacyl bromides were used in the reaction, the N-substitution reaction of isatin also finished with the formation of spi...

The title compound, C(35)H(35)ClN(4)O(3), resulted from a spiro-lactam ring closure of rhodamine B dye. The xanthene ring system is approximately planar [r.m.s. deviation = 0.050 (9) Å for the xanthene ring]. The dihedral angles formed by the spiro-lactam and 5-chloro-2-hy-droxy-benzene rings with the xanthene ring system are 87.9 (7) and 79.1 (7)°, respectively.

We show that FRET between Pacific Blue (PB) and Alexa488 (A488) covalently attached to a DNA scaffold can be reversibly controlled by photochromic switching of a spiropyran derivative. With the spiropyran in the closed spiro isomeric form, FRET occurs freely between PB and A488. UV-induced isomerization to the open merocyanine form shuts down the FRET process by efficient quenching of the PB ex...

A highly selective cascade reaction that allows the direct transformation of dienallenes to spirocyclobutenes (spiro[3.4]octenes) as single isomers has been developed. The reaction involves formation of overall four C-C bonds and proceeds via a palladium-catalyzed oxidative transformation with insertion of olefin, olefin, and carbon monoxide. Under slightly different reaction conditions an addi...

In the title compound, C20H18ClN3O3, the five- and six-membered heterocycles fused through a spiro C atom are inclined to each other at an angle of 87.4 (1)°. In the tricyclic ring system, the cyclo-hexene ring adopts an envelope conformation with the spiro atom as the flap. In the crystal, two sets of N-H⋯O hydrogen bonds link the mol-ecules into columns containing centrosymmetric R 2 (2)(7) r...

In the title compound, C(38)H(42)N(4)O(4)·C(2)H(6)O, prepared via a spiro-lactam ring-formation reaction in a rhodamine dye, the xanthene ring system is approximately planar (r.m.s. deviation = 0.0014Å) and subtends dihedral angles of 88.10 (3) and 86.92 (4)° with the spiro-lactam (r.m.s. deviations = 0.0012 Å) and benzene rings, respectively. The crystal structure consists of chains parallel t...

Abstract New spiro[cyclohexane-1,2'-thiazolo[4,5- b ]pyridine derivatives ( 3 – 23 ) were investigated. Then there is in vitro antimicrobial potency against possible organisms Staphylococcus aurous ATCC-47,077, Bacillus cereus ATCC-12228, Escherichia coli ATCC-25922, Salmonella typhi ATCC-15566, and Candida albicans ATCC-10231 tested utilizing commercially available antibiotics ampicillin as a ...

Tandem deoxygenation-neophyl-type radical rearrangement-electrophile trapping using xanthates from 7-azabenzonorbornadienes gives 3-exo-substituted 2-aza-5,6-benzonorbornenes, which in some cases undergo isomerisation to (aminomethyl)indenes. The starting xanthates are accessible in good yields and high enantiomeric ratios via asymmetric hydroboration of (aryne/pyrrole-derived) 7-azabenzonorbor...

The title bicyclic lactone, C(19)H(19)NO(3), is an inter-mediate in the synthesis of chiral α-methyl-prolines and branched C-methyl pyrrolidines; the absolute configuration was determined by the use of d-erythronolactone as the starting material. It exhibits no unusual crystal packing features, and each mol-ecule acts as a donor and acceptor for one C-H⋯O hydrogen bond.