Patent ID: 6716998
Filing Date: 2004-04-06
Classification: C07D

Abstract:
A stereospecific process for preparing a 2-yl chromene derivative comprising:(a) reacting a 2-hydroxy substituted styrene of formula (I) and an optically active 3-hydroxy-1-butene of formula (II) to form an optically active diene of formula (III) wherein R is a leaving group or a protected oxygen group, wherein R1, R2 and R3 are independently selected from hydrogen, a halogen atom, a cyano, azido, nitro, hydroxyl, carboxyl, acyl or carboxamido group, a C1 to C6 alkyl group, a 5- to 7-membered aromatic group optionally having as ring members up to 2 heteroatoms independently selected from O, N or S, a C5 to C7 membered aryloxy group, a C1 to C6 alkoxy group, alkanamido group having 1 to 6 carbon atoms in the alkyl chain, alkanesulfonamido group having 1 to 6 carbon atoms in the alkyl chain, an alkanoyloxy group having 1 to 6 carbon atoms in the alkyl chain, a perhalogenated C1 to C6 alkyl or alkoxy group, an amino group or a mono- or di-alkylamino having 1 to 6 carbon atoms per alkyl chain, or two of R1, R2 or R3, taken together, form a 5- to 7-membered saturated or aromatic carbocyclic or bridged carbocyclic ring, wherein the ring may i) optionally have up to two ring atoms selected from S, N, or O, ii) optionally have as a ring member up to 2 carbonyl groups or iii) optionally be substituted by 1 to 2 R5 substituents where each R5 substituent is independently selected from a halogen atom, a cyano, nitro or hydroxyl group, a C1-C6 alkyl group, a C1-C6 alkoxy group, a C3-C6 cycloalkyl group, a 5- to 7-membered aromatic group optionally having 1-2 ring atoms selected from N, O or S, or in spiro form a carbocyclic ring having 5 to 7 carbon atoms, or any combination of i), ii), or iii), wherein R4 is H or a C1-C6 alkyl group, andwherein R6 is a hydroxyl group, a protected oxygen group, or a leaving group; and(b) subjecting the diene of formula (III) to a ring closing metathesis polymerization reaction in the presence of a catalyst to stereospecifically produce an optically active 2-yl chromene derivative of formula (IV) wherein R1, R2, R3 and R6 are defined as in formula (III).