The Acid-Catalyzed Reaction of Styrene Oxide with Phenol and with 2-Naphthol

Mechanism of phenolic activation of Agrobacterium virulence genes: development of a specific inhibitor of bacterial sensor/response systems.

“…Benzyl vanillin (4 mmol) was treated with dimethyloxosulfonium methylide in dimethyl sulfoxide to afford 4-benzyloxy-3-methoxystyrene oxide (40%6) (26). This epoxide (0.4 mmol) and phenol (1 mmol) were dissolved in dry toluene, allowed to stand at room temperature overnight, and the entire mixture was chromatographed (SiO2 ether/pentane, 1:4) (27). The benzyloxy ether (38 ,mol) 131.4 (C-1'), 130.3 (2C, C-3"), 121.1 (C4'), 120.8 (C-6'), 116.1 (2C, C-2"), 115.1 (C-5'), 109.6 (C-2'), 83.2 (C-2), 68.0 (C-1), 56.6 (C-7').…”

Recent Progress in the Synthesis of 2,3-Dihydrobenzofurans

“…10 This compound is peculiar in being optically inactive although containing a chiral center ( Figure 2). More recently, benzodihydrofuran Downloaded by [Stanford University Libraries] at 01:07 07 October 2012 derivatives (3)(4)(5)(6)(7)(8)(9), all possessing interesting biological activities, have been found in several species of higher plants and in particular in Asteraceae. 11,12 The absolute configuration of many of these naturally occurring chiral 2-isopropenyl-2,3-dihydrobenzofurans was recently demonstrated by chemical methods.…”

“…In this respect, they found that the use of Rh 2 (S-DOSP) 4 in hexanes at -50 • C allowed the cyclization of aryldiazoacetate 36 to give the corresponding 2,3-dihydrobenzofuran 37 with a high yield and enantioselectivity (Scheme 35). 69…”

“…However, it is worth mentioning that the substitution pattern at the C-H insertion site is related to the nature of the chiral dirhodium catalyst used. For example, the use of dirhodium tetrakis[N-phthaloyl-(S)-tert-leucinate], Rh 2 (PTTL) 4 , allowed the cyclization to 2,3-dihydrobenzofurans to occur with a high stereoselectivity, in particular when the reaction occurred from insertion into a methylene C-H bond (Scheme 36). 70…”

“…a, Scheme 1), 3 nowadays can be found with transition metal catalysts (see Section VIII-2). The interaction of substituted styrene oxides with phenoxide ion pionereed by Guss et al,4 in which only marginal amounts of dihydrobenzofurans were obtained (eq. b, Scheme 1), has been very Scheme 1 recently transformed into a valuable stereoselective synthetic procedure by our research group (see Section II).…”