Latchezar S. Trifonov

Intramolecular diels-alder reaction of aryl allene phosphonates

Abstract Intramolecular Diels-Alder cyclization in aryl allene phosphonatesleads only in 1c to the tricyclic 2,3-oxaphospholene 2 , 2+2 dimerization being observed in the remaining cases.

Berbin-8-ones prom 2′-halogeno-1-benzylisoquinolines and metal carbonyls

Abstract The title compounds were synthesised from 2′-halogeno-1-benzyl-isoquinolines, their 3,4-dihydro- or 1,2,3,4-tetrahydro-derivatives and metal carbonyls under mild conditions.

Conformational energy analysis of substituted diphenylethanes: Part X. Conformations of some N-substituted 3-amino-2,3-diphenyl propanols and 4-amino-3,4-diphenyl-2-methyl-2-butanols. Emphasis on non-hydrogen bonded conformations

Abstract The conformational preferences in diastereoisomeric N -substituted 3-amino-2,3-diphenyl propanols and 4-amino-3,4-diphenyl-2-methyl-2-butanols were estimated by means of extensive empirical energy calculations with Momanys (rigid rotor approximation) and Allingers 1977 (full-relaxation calculations) force fields. Complete geometry optimization appears to be quite important in order to obtain results in satisfactory consistency with experimental data. Further improvements in this case are seen along with explicitly accounting for the possibility of intramolecular hydrogen bond formation and a readjustment of the torsional parameters for the four-atom unit C ar C al C al C ar .

A novel photochemical rearrangement of allenic esters

The alkyl allenic esters (1a–c) on irradiation are found to afford the cyclobutenones (2a–c) while the phenyl ester (1e) affords the photo-Fries product (4).