Tied back

Since going online in 1993, the joint venture has reaped large dividends from the P15/P18 blocks of Holland s Rijn field, some 40 km (25 miles) from Rotterdam. BP-Amoco processes 13 MMm (500 MMft ) of natural gas from the field each day also, nearly 2,000 m (12,300 bbl) of condensate are produced daily. The project marks the first time Dutch gas has been produced to sales specification at an offshore location. Seven reservoirs, developed separately, are tied back... 

Figure 4.2. Rotational-energy barriers as a function of substitution. Tbe small barrier ( 2kcal) in ethane (a) is lowered even further ( O.Skcal) if three bonds are tied back by replacing three hydrogen atoms of a methyl group by a triple-bonded carbon, as in methylacetylene (b). The barrier is raised 4.2 kcal) when methyl groups replace the smaller hydrogen atoms, as in neopentane (c). Dipole forces raise the barrier further ( 15 kcal) in methylsuccinic acid (d) (cf. Figure 4.3). Steric hindrance is responsible for the high barrier (> 15 kcal) in the diphenyl derivative (e). (After...

Stereoelectronic effects and nonbonded interactions are non-cooperative in the reactions of (E)-allylboronates and x-heteroatom-substituted aldehydes. Thus, while transition state 8 experiences the fewest nonbonded interactions (gauche pentane type, to the extent that X has a lower steric requirement than R3), transition state 9 is expected to benefit from favorable stereoelectronic activation (Felkin-type)58f. This perhaps explains why the reaction of 2,3-[iso-propylidenebis(oxy)]propanal and ( >2-butenylboronate proceeds with a modest preference (55%) by way ol transition state 9. This result is probably a special case, how ever, since C-3 of 2.3-[isopropylidenebis(oxy)]propanal is not very stcrically demanding in 9 owing to the acetonide unit that ties back the oxygen substituent, thereby minimizing interactions with the... 

Hair and loose clothing must be tied back. 

Secure loose clothing and tie back long hair. 

Long hair should be tied back to reduce the possibility of it catching fire. 

Open flame may ignite flammable chemicals, loose clothing, or hair alcohol, kerosene, potassium permanganate, hair, clothing Tie back hair. Avoid wearing loose clothing. Avoid open flames when using flammable chemicals. Be aware of locations of fire safety equipment. Notify your teacher immediately. Use fire safety equipment if applicable. 

A structure that prevents coplanarity prevents resonance stabilization to a corresponding degree. Thus the triptycyl radical has none of the stability of triphenylmethyl and the benzene rings are tied back in a position with the very maximum deviation from coplanarity.16... 

Long hair should always be tied back. 

Before lighting a Bunsen burner or candle, make sure that there are no flammable liquids nearby. Also, tie back long hair, and coniine any loose clothing. 

Be careful when working with an open flame, and tie back long hair. 

Turn on the gas and light the Bunsen burner. Create as hot a flame as possible. CAUTION Be careful when working with an open flame, and tie back long hair. 

Friedel-Crafts alkylation of 2,5-dimethylthiophene with f-butyl chloride and A1C13 gave only the mono-r-butylated product (49) and none of the expected di-f-butylated thiophene (50). In order to facilitate di-r-butylation at positions 3 and 4, the substituents at 2 and 5 were tied back in the thiophenophane (51). This on alkylation gave, unexpectedly, the rearranged mono-f-butyl derivatives (52 30%) and (53 57%), and the di-f-butyl derivative (54 12%). The structures of the products were proved by NMR, Raney nickel desulfurization and independent synthesis (75T2551). One other such isomerization under Friedel-Crafts conditions had been previously reported (65JOC1058) 2,5-di-f-butylthiophene isomerizing to 2,4-di-f-butylthiophene. 

Manganese and Rhenium Complexes with Tied-Back Phosphites... 

Complexes featuring the tied-back phosphite ligand, P(OCH2)3CMe, have been of considerable interest to us for the binding and activation... 

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