Stereochemical Inversion of (R)-5-Hydroxymethyl-3-tert-butyl-2-oxazolidinone or (R)-5-Hydroxymethyl-3-isopropyl-2-oxazolidinone to the Corresponding (S)-Isomer

3-Bromo-5-tert-butyl-2-hy­droxy­benz­alde­hyde

The mol-ecular conformation of the title compound, C(11)H(13)BrO(2), is stabilized by an intra-molecular O-H⋯O hydrogen bond. All non-H atoms except the methyl groups lie approximately in a common plane (r.m.s. deviation = 0.011 Å).

(6R)-2-tert-Butyl-6-[(4R,5S)-3-isopropyl-4-methyl-5-phenyl­oxazolidin-2-yl]phenol

In the title compound, C(23)H(31)NO(2), the lone pair on the nitro-gen atom is oriented to facilitate intra-molecular hydrogen bonding with the hydr-oxy group residing on the phenyl substituent. The five-membered ring adopts an envelope confornmation with the O atom at the flap. The absolute stereochemistry was verified by measurement of optical activity using a digital polarimeter.

tert-Butyl (2S)-2-{3-[(R)-bis­(tert-but­oxy­carbon­yl)amino]-2-oxopiperidin-1-yl}-3-methyl­butano­ate1

The title compound, C(24)H(42)N(2)O(7), is a chiral lactam-constrained amino acid with a six-membered ring backbone and isopropyl and tert-butyl ester side chains. The conformation of the six-membered ring can be described as a half chair, with two CH(2) C atoms lying 0.443 (1) and -0.310 (1) Å out of the best plane of the other four atoms (mean deviation = 0.042 Å). Both N atoms are sp(2) hybr...

5-tert-Butyl-2-hy­droxy-3-(2-thien­yl)benzaldehyde

In the crystal structure of the title compound, C(15)H(16)O(2)S, the thio-phene ring is essentially planar (r.m.s. deviation = 0.006 Å for all non-H atoms) and roughly coplanar with the benzene ring, the dihedral angle between the mean planes of the rings being 4.35 (8)°. An intra-molecular O-H⋯O hydrogen bond is observed between the OH group and the aldehyde O atom.

( 3 aR , 8 b 8 , 5 ' R ) 3 - [ ( 2 , 5 -