Premium
Syntheses and CD studies of new cholesteno[4,3‐ d ]‐ and ‐[7,6‐ d ]pyrimidines
Author(s) -
Hasan Mashooda,
Rashid Naghmana,
Khan Khalid Mohammed,
Perveen Shahnaz,
Snatzke Günter,
Duddeck Helmut,
Voelter Wolfgang
Publication year - 1995
Publication title -
liebigs annalen
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.825
H-Index - 155
eISSN - 1099-0690
pISSN - 0947-3440
DOI - 10.1002/jlac.1995199510262
Subject(s) - chemistry , helicity , pyrimidine , derivative (finance) , sign (mathematics) , quadrant (abdomen) , spectral line , methane , stereochemistry , organic chemistry , mathematics , physics , medicine , mathematical analysis , particle physics , pathology , astronomy , financial economics , economics
The syntheses of 5α‐ and 5β‐cholest‐3‐eno[4,3‐ d ]pyrimidines ( 7 ) and ( 7′ ) could be achieved by using the hydroxymethylene derivative of cholestan‐4‐one ( 5 ) prepared from cholesterol ( 1 ). Their 2′‐derivatives 7a‐7d and 7′a‐7′c were also synthesized. 5α‐Cholest‐6‐eno[7,6‐ d ]pyrimidine ( 13 ) was prepared by the reaction of 5α‐cholestan‐7‐one ( 12 ) with tris‐(formylamino)methane. The CD spectra exhibit at least three Cotton effects between 300 and 210 nm, a first CD band around 290, a second one around 260, and a third one around 220 nm. An earlier developed quadrant rule can be applied to the determination of the sign of the first CD band, while the suggested helicity rule allows prediction of the third CD band.