PROCESS FOR PREPARATION OF BICYCLOHEPTANE DERIVATIVES

摘要

Prepn. of a 2-exo-hydroxy-7-oxabicyclo (2,2,1) heptane (I) [R1=H, C1- 10 (un)substd. alkyl; R2=H, C1-6 alkyl; R3=H, Cl, Br, C1-4 alkyl or haloalkyl; R4=H, C1-4 alkyl or haloalkyl; R5=H, C1-4 alkyl, haloalkyl, hydroxyalkyl, alkoxy! comprises cyclization of the corrsesp. cis-3,4-epoxycyclohexanol (II) by acid treatment. Thus, (+)-terpinen-4-ol in PhMe contg. vanadiumbis (2,4-pentanedioate) oxide is added to 90% Me3COOH to give an intermediate (II) (R1=Me2CH,R2=Me,R3,R4,R5=H) which is treated with p-MEC3H4SO3H to give (I) (R1=Me2CH,R2=Me,R3,R4,R5=H).