General synthesis for chiral 4-alkyl-4-hydroxycyclohexenones

Abstract

[reaction: see text] Some selective transformations of resorcinol-derived cyclohexadienone are reported. Efforts led to a structure reported to display anticancer properties. On the basis of the results, the structures for natural products reported to contain a 4,6-dihydroxy-4-alkyl-cyclohexenone nucleus are corrected.

Figure 1

Original assignments for agents found in T. guianensis Aublet.

Figure 2

o-Quinone methide cascade leading from 6 and 7 to 2 and 8.

Figure 3

Probable transition states leading to (−)-11 and the unseen diastereomer.

Figure 4

Unusual transformation that enables ether cleavage.

Scheme 1

Preparation of the 16-Carbon Grignard Reagent

Scheme 2

Elaboration of the o-Quinone Methide Intermediate

Scheme 3

Dearomatization and Diastereoselective Synthesis of 11

Scheme 4

Diastereoselective Synthesis of 14

Scheme 5

Completion of Synthetic 1