Patent ID: 6297416
Filing Date: 2001-10-02
Classification: C07C

Abstract:
A process for preparing .beta.-carotene, represented by Formula 3 ##STR16##which comprises the steps ofa) providing a sulfone compound of Formula B ##STR17##(b) deprotonating the sulfone compound of Formula B and reacting not more than 1/2 equivalent, based upon the sulfone compound, of an allylic sulfide, represented by Formula C ##STR18##wherein X is a halogen, to provide a sulfide compound of Formula D ##STR19##(c) oxidizing the sulfide compound of step (b) to provide a sulfone compound of ##STR20##(d) subjecting the sulfone compound of step (c) to a Ramberg-Backlund reaction to provide 11,20-di(benzenesulfonyl)-11,12,19,20 tetrahydro-.beta.-carotene of Formula F ##STR21##(e) reacting the product of step (d) with a base to obtain .beta.-carotene of Formula 3.