Synthesis, structure analysis, and stereochemistry of some reactions of cis- and trans-2,2,5-trimethyl-3-phenyl-1,3-oxaphospholane

Abstract

The syntheses of cis-and trans-2,2,5-trimethyl-3-phenyl-1,3-oxaphospho~ane are reported and a detailed analysis of the NMR spectra given from which stereochemical assignments were made and conformational structure suggested. Hydroxide cleavage of cis-and trans-3-benzyl-2,2,5-trimethyl-3-phenyl-l,~-oxaphospholanium bromide occurred stereospecifically with retention of configuration a t phosphorus to yield the corresponding diastereomers of 2,2,5-trimethyl-3-phenyl-1,3-oxaphospholane %oxide

Cover Picture: Catalytic Molecular Logic Devices by DNAzyme Displacement (ChemBioChem 7/2014)

“…In contrast, the reaction yield with acetophenone was just 30 %. This procedure was improved to give better yields by Marsi, who obtained products 62 in 70 % yield from reactions with acetone 47. Both 1,3‐oxaphospholanes 63 48 and oxaphosphorinanes49 have recently been synthesized by this method (Scheme ).…”

P−H-Functionalized Phosphanyl Alcohols: RHPCH2CHMeOH and 2-PHR-1-OH-cyclo-C6H10 (R = Ph, 2,4,6-Me3C6H2, 2,4,6-iPr3C6H2) and Molecular Structures of (CR,CR,PR/CS,CS,PS)-2-PH(2,4,6-iPr3C6H2)-1-OH-cyclo-C6H10 and its Dilithio Salt [Li2(THF)0.5{(CR,CR/CS,CS)-2-P(2,4,6-iPr3C6H2)-1-O-cyclo-C6H10}]4

“…The PϪH-functionalized phosphanyl alcohols RHPCH 2 CHMeOH [R ϭ Ph (1), [2,7] Mes (2), Tipp (3)] were obtained by ring-opening of propene oxide with LiPHR, followed by hydrolytic workup and distillation [Equation (1)].…”

“…[3] In 1997, Thiel et al used the stereoselective ring-opening of cyclohexene oxide by lithium diphenylphosphanide to prepare chiral phosphanyl alcohols. [4] Primary [3,5] and secondary [6,7] phosphanyl alcohols have hitherto been used for the preparation of organic P heterocycles. Their ligation properties are, however, largely unstudied.…”

“…Syntheses of 1 [2,7] and 4 [2] have been reported previously, but both compounds were only characterized by elemental analysis and IR spectroscopy. [2] Although a 1 H NMR spectrum has been reported for 1, no diastereomers were observed.…”

“…[2] Although a 1 H NMR spectrum has been reported for 1, no diastereomers were observed. [7] Results and Discussion Synthesis of RHPCH 2 CHMeOH [R ‫؍‬ Ph (1), 2,4,6-Me 3 C 6 H 2 (Mes) (2), 2,4,6-iPr 3 …”