title: Total (1)H NMR assignment of 3β-acetoxypregna-5,16-dien-20-one.
abstract: This work describes the total and unambiguous assignment of the 750 MHz (1)H NMR spectrum of 3β-acetoxypregna-5,16-dien-20-one or 16-DPA (1), the well-known intermediate utilized in the synthesis of biological important commercial steroids. The task was accomplished by extracting the coupling constant values in the overlapped spectrum region by HSQC, and using these values in the (1)H iterative full spin analysis integrated in the PERCH NMR software. Comparison of the experimental vicinal coupling constants of 1 with the values calculated using Altona provides an excellent correlation. The same procedure, when applied to the published data of progesterone (2) and testosterone (3), afforded an acceptable correlation for 2 and a poor correlation for 3. In the last case, this suggested the reassignment of all four vicinal coupling constants for the methylene signals at the C-15 and C-16 positions, demonstrating the utility of this methodology.
authors.affiliation: Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, México, D.F. 07738, Mexico.
authors.forename: Elvia
authors.initials: E
authors.lastname: Becerra-Martinez
authors.affiliation: Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, México, D.F. 07738, Mexico.
authors.forename: Karla E
authors.initials: KE
authors.lastname: Ramírez-Gualito
authors.affiliation: Escuela Nacional de Medicina y Homeopatía, Instituto Politécnico Nacional, México, D.F. 07320, Mexico.
authors.forename: Nury
authors.initials: N
authors.lastname: Pérez-Hernández
authors.affiliation: Departamento de Química, Centro de Investigación y de Estudios Avanzados del Instituto Politécnico Nacional, Apartado 14-740, México, D.F. 07000, Mexico. Electronic address: pjoseph@nathan.cinvestav.mx.
authors.forename: Pedro
authors.initials: P
authors.lastname: Joseph-Nathan
mesh_terms: D008958:Models, Molecular; D008968:Molecular Conformation; D011282:Pregnenediones / Q000737:chemistry*; D066244:Proton Magnetic Resonance Spectroscopy / Q000592:standards; D012015:Reference Standards; D012984:Software
chemical_list: C469666:3-acetoxypregna-5,16-diene-20-one; D011282:Pregnenediones
keywords: 3β-Acetoxypregna-5,16-dien-20-one; Iterative (1)H NMR analysis; Progesterone; Testosterone