Patent ID: 8759523

Claim:
A process comprising the step of dehydrating a compound of Formula (I): to form a compound of Formula (II): wherein R 1 is —CH═CH—R 8 or —CH 2 —CH═CH—R 9 ; R 2 is C 1 -C 4 -alkyl; R 3 is H, C 1 -C 4 -alkyl, benzyl, or -phenyl-(R 10 ) x ; each R 4 is independently H, or C 1 -C 4 -alkyl; each R 5 and each R 6 are independently H, C 1 -C 4 -alkyl, —O—C 1 -C 4 -alkyl, or —S—C 1 -C 4 -alkyl; R 7 is R 8 or —CH 2 —R 9 ; R 8 is H, C 1 -C 4 -alkyl, or -phenyl-(R 10 ) x ; R 9 is H, C 1 -C 3 -alkyl, or -phenyl-(R 10 ) x ; each R 10 is independently halo, C 1 -C 6 -alkyl, —O—C 1 -C 4 -alkyl, or —S—C 1 -C 4 -alkyl; and each x is independently 0, 1, or 2 wherein the process is carried out in the presence of an organic base and a dehydrating agent selected from Tf 2 O or P 2 O 5 .