An efficient and facile method for the synthesis of a broad series of benzofurans and naphthofurans is described. The direct intramolecular cyclodehydration of aryloxyketones in the presence of titaniumtetrachloride affords the corresponding benzofurans and naphthofurans with good regioselectivity and yields.
A highly efficient enantioselective synthesis of chiral β‐aryloxy alcohols by the RuCl2[(S)‐SDP][(R,R)‐DPEN]} [(Sa,R,R)‐1a; SDP=7,7′‐bis(diarylphosphino)‐1,1′‐spirobiindane; DPEN=trans‐1,2‐diphenylethylenediamine] complex‐catalyzed asymmetric hydrogenation of racemic α‐aryloxydialkyl ketones via dynamickineticresolution (DKR) has been developed. Enantioselectivities of up to 99% ee with good to
6-Aryloxy-2-oxo-1-aza-4-oxa(or thia)-spiro [4,5]decane compounds. These compounds are represented by the formula: ##STR1## in which A stands for an oxygen or sulfur heteroatom; R.sub.1 and R.sub.2 are each H, lower alkyl or aryl such as phenyl; X is H, a halogen atom such as chlorine or fluorine or a lower alkyl. Compounds according to the invention are useful as stimulating agents for vigilance, as psycho-stimulators and genesic stimulators.
A compound represented by the formula (I):
wherein R1 is an oxo group, =N-R or the like; a group represented by the formula:
is a group represented by the formula:
R2 is a group represented by the formula:
R3 and R4 are each H, or C1-C6 alkyl, C3-C6 cycloalkyl, C1-C6 alkoxy, C1-C6 alkylamino, di(C1-C6)alkylamino or C1-C6 alkylthio, each of which is optionally substituted; and R5 is H, or C1-C6 alkyl, C2-C6 alkenyl, cyclic group, each of which is optionally substituted, -CO-R8 or -O-R8', or a salt thereof. The compound of the present invention is useful as a drug for the prophylaxis or treatment of circulatory diseases, metabolic diseases and/or central nervous system diseases.