Deposited in DRO : 08

The preparation of a number of alkyl and alkoxy derivatives of pentacyclo[5.4.0.0.0.0]undecane8,11-dione derivatives utilising a cheap, practical, low energy, “green”, single-pass continuous flow photochemical reactor is reported Their H and C NMR spectra are fully assigned, revealing some general characteristics not previously reported for this class of compound, which should aid the assignment and prediction of the NMR spectra of new PCUD derivatives. Introduction Pentacyclo[5.4.0.0.0.0]undecane8,11-dione derivatives (PCUD’s) are an interesting group of molecules prepared by the photochemical isomerization of the product of a Diels-Alder reaction between a cyclopentadiene and a 1,4-benzoquinone molecule (Figure 1). With the ready availability of both substituted benzoquinones and substituted cyclopentadienes a wide variety of derivatives have been prepared and studied. The archetypal molecule is the unsubstituted diketone 1p, first prepared by Cookson from the [2+2] photocyclisation of tricyclo[6.2.1.0]undeca-4,9-diene-3,6dione 1t, which encompasses a series of two five membered rings (black) bridged with a four membered ring (red) and a further five membered ring (blue) (Figure 1). These pentacyclic structures have been incorporated into many molecules capable of antifungal and antibacterial R2 O