Bis(trimethylsilyl)ketene acetals as 1,3-dinucleophiles. Formation of an anhydride from (pentacarbonyl)(phenylethoxy)tungstacarbene

3-Phenyltetrahydrofuran-2,5-dione

“…Normally, a twist or envelope form for the THF-2,5-dione ring was expected. In the title structure, the 2,5-dione ring is essentially planar, with the chiral atom C2 within the plane, whereas in the 3,3-dimethyl-2,5-dione ring (Rudler et al 2005), a flattened envelope form was observed, with the chiral atom C1 being slightly out-of-plane. Interestingly, the title molecule has a dihedral angle of 85.68 8 (Jeffrey & Saenger, 1994, p. 157).…”

“…For the crystal structure of the related compound, 3,3-dimethyl-4-phenyltetrahydrofuran-2,5-dione, see: Rudler et al (2005). For hydrogen bonds, see: Desiraju & Steiner (2001); Jeffrey & Saenger (1994).…”

“…1). A similar compound, 3,3-dimethyl-4-phenyltetrahydrofuran-2,5-dione, (Rudler et al 2005) crystallized in the centrosymmetric space group P2 1 /n, with racemic forms R* and S* in the structure.…”

Reactions of Bis(trimethylsilyl)ketene Acetals with Several Activated Organic Substrates

“…The use of suitable metal complexes allows the synthesis of γ‐lactones through 2+3 cycloaddition between, for example, 1a and carbon–carbon double bonds. Similar addition to 4 , a Fischer carbene complex of tungsten, led to the formation of anhydride 5 , Scheme …”

“…Bis(trimethylsilyl)ketene acetals 1 can be categorized into two forms as nucleophilic agents (Scheme ). The structure formed by route A has been used in reactions with epoxides to form γ‐butanolides through intramolecular reaction, whereas the second form can be used as a precursor of 1,3‐C,O dinucleophiles produced through successive cleavage of the two oxygen–silicon bonds according to route B …”