SYNTHESIS OF VITAMIN A AND RELATED COMPOUNDS 



725 



c„. 



/ \ H H I ,0 



HeC C' c :c- c- c-h 



I II 2: H 



HzC C 



\ / \ 



C CHj 



Hz 



CH3 

 + CjHjO-CHj'CHj'CHs'C-C! CMgBr 



CH, 



•XTTT 



OMgBr 



+ Ci,H50-CH2>CH2-CH:C-C: CMgBr 

 XLIII 



HjC CHj \ HjC CHj 



C CH, C CHj CH, 



/\hh|h h /\hh|h Ih 



HtC C • C : C- C- C • C : C- 0- CHj'CHj'CH.OCsHj HjC C • C : C • C • C • C : C • C : C • CH, • CH;0C,H5 



H 



HzC C 



\ / \ 



C CHj 



Hi 



OH 



OH "XOY 



H 



HzC C 



\ / \ 

 C CHj 



H2 



HjC CHj 



C CHj C H 5 



/ \ H H I H I H H 



H,C C • C : C • C; C • C : C- C : C • C -CHzOCjHs 



I II H 



H,c c 3a3i 



\ / \ 



C CH, 



Hj 



OH 



yuv 



IMPARTIAL HYDROGENATION 

 (2I0EHYDR0BR0MINATI0N 



(IIPARTIAL HYOROOENATfON 

 iZlOEMYORATION OR 



DEMYDROHALOGENATION 



t t » 



HjC CH3 



r- C H 3 CHj 



/\ hhIhhhIhh 



HcC C-C:C'C:C'C:C'C:C'C -CHjOC h, 



• I II S3E 



HjC C 



\ / \ 



C CHj 



H? 



Synthesis of Vitamin A Homologues 



